added firebase

src/app/app.module.ts

@@ -13,6 +13,8 @@ import {MaterialModule} from "./material.module";
 import {CalibrateComponent} from "./map/calibrate/calibrate.component";
 import {MatInputModule} from "@angular/material";
 import {PermissionsComponent} from "./permissions/permissions.component";
+import {AngularFireModule} from "@angular/fire";
+import {AngularFirestoreModule} from "@angular/fire/firestore";
 
 @NgModule({
     declarations: [
@@ -24,6 +26,8 @@ import {PermissionsComponent} from "./permissions/permissions.component";
     ],
     imports: [
         AgmCoreModule.forRoot({apiKey: 'AIzaSyDFtvCY6nH_HUoTBNf_5b-E8nRweSLYtxE'}),
+        AngularFireModule.initializeApp(environment.firebaseConfig),
+        AngularFirestoreModule.enablePersistence(),
         AppRouting,
         BrowserAnimationsModule,
         BrowserModule,

src/app/home/home.component.ts

@@ -2,6 +2,7 @@ import {Component} from "@angular/core";
 import {Observable, timer} from "rxjs";
 import {map, take} from "rxjs/operators";
 import {Router} from "@angular/router";
+import {SyncService} from "../map/sync.service";
 
 const chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
 
@@ -13,7 +14,7 @@ export class HomeComponent {
     phrase = 'If you\'re into that';
     typedText: Observable<string>;
 
-    constructor(private router: Router) {
+    constructor(private syncService: SyncService, private router: Router) {
         this.typedText = timer(750, 50).pipe(take(this.phrase.length), map((i: number) => this.phrase.substring(0, i + 1)));
     }
 
@@ -21,7 +22,7 @@ export class HomeComponent {
         let mapCode: string;
         do {
             mapCode = Array(16).fill(0).map(() => chars[Math.round(Math.random() * chars.length)]).join('');
-        } while (false);
-        this.router.navigate(['/', mapCode]);
+        } while (await this.syncService.exists(mapCode));
+        return this.router.navigate(['/', mapCode]);
     }
 }

src/app/map/sync.service.ts

@@ -0,0 +1,24 @@
+import {Injectable} from "@angular/core";
+import {AngularFirestore, AngularFirestoreCollection, DocumentSnapshot} from "@angular/fire/firestore";
+import {map} from "rxjs/operators";
+
+@Injectable({
+    providedIn: 'root'
+})
+export class SyncService {
+    private collection: AngularFirestoreCollection;
+
+    constructor(private db: AngularFirestore) {
+        this.collection = this.db.collection('Maps');
+    }
+
+    async exists(mapCode: string) {
+        return (await this.collection.doc(mapCode).ref.get()).exists;
+    }
+
+    load(mapCode: string) {
+        return this.collection.doc(mapCode).snapshotChanges().pipe(map((snap: any) => {
+            return Object.assign({}, snap.data, {delete: snap.ref.delete, set: snap.ref.set, update: snap.ref.update});
+        }))
+    }
+}